I think the two man tent is a better idea for most people. One man tents are often like canvas coffins - they will fit you and not much else. A two man tent has a lot more space for your rucksack, etc.
You kind of get what you pay for - a cheapish tent (from a decent brand like Vango) will be sturdy but heavier than something from a posher brand (Wild Country) which again will be heavier but cheaper than its cousin in Terra Nova. The trick is to get something that suits you, and that matches your budget, but is hopefully as light as you can get for the money. The fact is that once you've bought a tent, there isn't a huge amount of modding you can do to it. You havn't give a budget, but I'm assuming up to sixty quid isn't a bad level, with the next level staring at a botu a hundred.
Basic but reliable is good, and Vango is a good place to look - solid and not the lightest, but well thought of at decent prices. This
one is about as cheap as its going to get (they have the two person one for a tenner more). I have no idea what they are like, but 2.17kg for a 2 man tent at that price isn't bad at all. Uttings have them in
green for the same price.
Vango will do more expensive tents as well, such as the Conshee, but think more a £100 and over. Go Outddors isn't a bad place to start, since they will often have some of their own range set up - its really useful to just sit inside one and see if it works for you - size and layout. Their OEX own-brand range is the one they have for hikings, as opposed to their Freedom Trail cheapie stuff for festivals and the like. OEX stuff hasn't got a huge number of reviews online, but seems decent. They have a
one man tent, for about £60, which weighs in at 1.58kg, and a
two man tent which comes in at 3kg for £70. To put that into context, my Wild Country Zephyros 2 is about 1.8kg, but it does retail about the £130 mark.
Have a look at what they've got, and ask if there are any markdown or end of lines - you might do well.
Wild Country is the cheaper brand from Terra Nova, and the Zephyros is well thought of for weight and design, without spending a fortune. But its a bit more pricey than Vango. However, Ebay can be your friend, and I think this one is worth
£40-50 with no problem - a small hole in the groundsheet is easy to patch and a new guyline is a couple of quid. Or
£75 for the one man version (thats a good deal). I also found this
Vango - £25 with P & P, and you'd have to a replace a pole section (ebay should have them) and well as pegs. Not bad, but the Wild Country one is much better value!
I did find a
berghaus tent on ebay as well at £70 - you'd have to look at the reviews, but it is a bit
heavy. Actually, there is a
berghaus mountain tent for a good price, but its a bit OTT for your needs!
I'd do some research, find out whats best for you in terms of size, find the lightest you can for your money, and look around.
Blacks will often do surprisingly good deals (the Vango is pretty cheap there), Go Outdoors will often have tents set up, and Cotswolds have always done well in setting up a tent if your interested and they are quiet. Trekkit is online and has good service, and I'd recommend getting
this book - you get get it for about £7 used on Amazon, and its very good for renovating and repairing second hand stuff - a good way to save money!